Portable liquid oxygen unit



Feb. 24, 1948. .1. A. WEAVER 2,436,411

PORTABLE LIQUID, oxmnn UNIT Filed Dec. 11, 1945 2 Sheets-Sheet 1 IV Vf/V TUB (/0611 A Ware! 197' T OENE Y5 Patented Feb.

. UNITED STATES PATENT OFFICE.

marmanqum oxrcnn UNIT m a. Weaver, Detroit, Mich. a plication December 11, 1945. Serial No. 034,329 new. (case-1) oi-mm under the m. of March a, less."

' nmendednpril 30, 1928; 370' 0. v(9:. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes without payment to me .of any royalty thereon.

This invention relates to a portable liquid oxygen unit, having special reference to a small compact unit which may, if desired, be carried about on the person of the user to supply him with gas phase oxygen for a period of several hours.

An object of this invention is to provide a device of this character having a liquid oxygen storage receptacle suspended within a vacuum jacketed container, and means to intermittently transfer a small quantity of the liquid omgen to an uninsulated enclosure to thereby subject it to atmospheric heat to convert it into gas phase oxygen.

Another object is to so construct and arrange the device that the recurrence of the conversion period is automatically responsive to the volume of gas phase oxygen being used.

Another object is to gimballysuspend the liquid oxygen storage receptacle within the vacuum jacketed container in such a manner that the liquid phase inlet and the gas phase outlet of the receptacle will always be respectively at the bottom and the top thereof with respect to the gravity axis regardless of the position of the housing and the other elements of the device. 7

Another object is, to provide gauge means with liquid oxygen and at the other end another hub 20 is provided for attachment, an oxygen mask through whichoxygen is taken by the user after it has been converted to a gaseous state.

Centrally disposed within the housing i0 is a jacket 22 having a dome 24 atthe top from which the jacket is supported in the housing by-a uni-' versal joint 28. A washer like disc 28 is carried by the dome 24, and a ring 30 carried by the housing I ii surrounds the washer loosely, leaving only a very slight swinging movement of the jacket 22 on the universal joint 28. The ring 30 has a shoulder 32 and the disc 28 may preferably just touch this shoulder when the unitcontains no liquid oxygen. The radius of the disc 28 7 should be equal to the distance from the disc to whereby the amount of liquid o gen remaining in the device may be read directly at all times.

Other objects and advantages will become apparent from a consideration of the description taken in conjunction with the drawings, wherein:

Fig. 1 is a vertical axial sectional view of a de-.

vice which embodies the principles of my invention.

Fig. 2 is an enlarged detail sectional view of ;he pressure regulating valve of my device in the men or unactuated position.

Fig. 3 shows the valve of Fig. 2 inthe closed )1 actuated position.

Fig. 4 is an enlarged detail elevational view,

Jartly in section, of the gauge for indicating the olume of liquid oxygen remaining at any time. Like reference characters refer to like parts hroughout the several views.

The several elements of my improved device are lssembled and supported within a more or less- :ylindrical protective housing I 0 which is open 0 the atmosphere at the bottom as at l2, the pening being covered by ascreen ll held on by crews it. At one end the housing has a centrally lisposed hub I8 through which the device is filled the center otthe jacket 22; The purpose 01 thus limiting the swinging movement of the jacket 22 on the universal joint 28 will hereinafter appear. Within the jacket 22 is a spherical container M which is spaced apart from the jacket by bridges 38 which are preferably of low heat conductivity, leaving a jacketed space 38 between the container 34 and jacket 22 which extends also up into the dome 24. The jacketed space 38 is evacuated and sealed whereby the container 34 is heat insulated.

Gimbaily supported within the container 34 by means of a gimbal ring 40 is a spherical receptacle 42 which is rotatable on an axis which is normally horizontal, as shown, by reason of the pivot bearings 44 and 43 of the receptacle, which have rotative bearing in the ring, the ring 40 being in turn rotatable on an axis which is normally vertical, by reason of the pivot bearings 58 and W of the ring which have rotative bearing in the container 34. A weight 52 is fixed in the bottom of the receptacle, and a liquid phase orifice 54 extends through the weight and through the wall of the receptacle for connecting the inside of the receptacle to the space 58 between the receptacle.

it are fast in the top and bottom respectively of the receptacle 42 and are concentrically positioned with respect to the opening 08 and the oriflce 04.

The gimbal ring 48 is provided with a duct which connects the pivot bearing 40 to the pivot bearing 00. Ring 40 may be made of flattened tubing bent to circular form in which case the duct 00 may extend throu hout the entire circumference. The space at the upper end of the bearing 00 is connected by a tube 08 to a relief valve II, the tube 03 making at least one turn in the evacuated space 38 before connectingwlth the valve. Valve I0 is adjusted to maintain a pressure of 40 p. s, i.. this selected pressure value being by way of example only.

A filler tube I2 extends from the filler hub I8 through the wall of the jacket 22 at I4 at which point it is sealed, then through the evacuated space 34 to a check valve I0. That portion oi the fllier tube I2 which is outside the jacket 22 is made flexible as at 00. while that portion within the jacket may be flattened as at 80 in order that it may occupy less space.

From the check valve I0, a branch tube 82 makes at least one turn before entering the container 34 at 04, and a second branch 80 goes to the inlet of the automatic pressure responsive valve 88. Valve 88 discharges into a warming coil 80. the turns of which are preferably laid on the outside of the jacket 22 and may be sol-.

dered or similarly secured thereto. The coil 80 80 discharges through the tube 08. part of which is flexible as at 8i, into the regulator 82 which may. be a diluter demand regulator of conventional design or similar device. A relief valve 84 prevents the pressure withinthe coil 80 rising above a a predetermined value which may preferably be about 60 .p. s. i. A conventional flow meter 00 may be provided to indicate the rate at which gas phase oxygen is being drawn from the demand regulator.

The 'automatic pressure responsive switch, broadly designated by the numeral 88, comprises an internally threaded valve body 80 within which a flanged valve seat member I00 is held by an externally threaded casing I02. A metal bellows I04- within the casing I02 has one end sealed to a washer I00 and the other end to a flanged hub, I08, the washer being clamped between the end of the casing I 02 and the flange of the valve seat member I00 and the flanged hub I08 being slidable axially within the casing. I02. A valve head IIO has its stem II2 threadedly secured in the hub I00, a spring II4 contained in a recess I IS in the valve seat member i00 being provided to urge the valve head H0 on to its seat as seen in Fig. 3. An outlet passageway II8 extendslaterally from the recess H0 for connection to the warming coil 90, whereby the space within the coil 80 is in communication with the inside of the bellows I04 and the pressure within the bellows therefore acts in conjunction with the spring I I4 to maintain the valve I I0 in closed position. The space H8 around the valve head H0 is in com- 'munication with the branch tube 80 whereby,

when the valve head H0 is ofl its seat the branch tube 80 will be in direct communication with the warming coil 80. The space I20 within the casing I02 outside the metal bellows I04, and the space I22 at the end of the flanged'hub I08,

are vented tothe atmosphere. A valve opening 7 spring I24 acts against the end of the flanged hub I08 to urge the valve head H0 to the open position seen in Fig. 2. A cup-shaped nut I20 is externally threaded to engage internal threads in the casing I02 for adjusting the valve opening 4 spring I24. For illustrative purposes only it may be assumed that the nut I is so adjusted as to cause the valve head 0 to rise from its seat when the pressure within the warming coil 90 and passageway IIB drops to p. s. i.

The mechanism shown in Fig. 4 for visual indication of the volume of liquid phase oxygen remaining at any time in the device, is broadly designated by the numeral I28 and is in the form of a spring weighing scale with the indicating means preferably graduated in litres and so arranged that the correct volume will be indicated in any position of the device not more than ninety degrees from the upright position.

.The operative portion of the volume indicating mechanism I20 is contained within a case I30 integral with or attached to the top of the housing I0. An inverted cup I32 is rotatable on an antifrlction bearing I34 in the bottom of the case I30, and carries a pointer I30 which may cooperate with a circular graduation on the underside of the glass I38 or on the top of the web I40 as desired.

Extending upwardly from the upper member of the universal joint 20 is an operating stem I42 having at its upper end a flange I44 which rests on the top of a spring I40, the lower end of the spring resting on the bottom of the case I30. A shoulder I48 on the stem limits vertical travel of the stem by contact with the bottom of the case.

In order that a vertical movement of the universal joint 20, due to a change in volume of the liquid phase oxygen within the container 34 and parts associated therewith, may produce a rotary movement of the cup I32 and pointer I80, a helical slot I80 is cut through the side wall of the cup, and a pin I02 has the inner end fast in the flange I44 and the main body of the pin in so the slot I50. Since the jacket 22. dome 24 and contained parts cannot. rotate materially due to the connections 10 and 8|, the cup and pointer are rotated by vertical movement of the stem I42. A hairspring I04 is provided to minimize backlash of the cup I32, one end being attached to the bearing member I34 and the other to the cup. The spring I40 should preferably be such that the washer 20 just touches the shoulder 32 when the device is empty and the shoulder I48 just touches the bottom of the cup I30 when the device is full. The spiral groove I50 may then be cut so as to make one complete turn when the spring I40 is compressed this amount.

The operation of the unit shown is substantially as follows:

Liquid oxygen under a pressure of approximately p. s. i. is brought from a source of supply through an insulated metal hose and disconnect attachment (not shown) through the hub I8 and tubing I2, I0, and 80, through the check valve I0. Since the pressure responsive valve 08 is normally'open when the device is empty, some liquid phase oxygen will pass through the tube and valve 88 into the warming coil 90, which, being exposed to atmospheric heat, will generate enough pressure in a matter of several seconds to close the valve 88.

When the pressure responsive valve 88 is closed, fluid will thereafter flow only through the tube 82 and into the container 34 at 04, pass around the gimbal ring 40 and through the orifice 54 into the receptacle 42. Air or gas left in the receptacle 42 when it was not in use may pass out through the opening 60, tube 50. gimbal ring duct 60, out through the pivot bearing 00 and tube 08 and the relief valve II. Since the relief valve is set at p. s. i. and the source or supply is at a pros sure of 65 p. s. 1., the relief valve will openand allow the air and gas to escape as soon as the pressure within the device exceeds 40 p. s. 1.,

When the gauge I28 indicates that the device is properly filled, the source of supply may be disconnected from the hub l8 and a cap screwed thereover.- The check valve 16 will hold the pressure until the hub-has been capped.

Thereafter when the demand regulator 92 has drawn enough gas phase oxygen from the warm.

. ing coil 90 to reduce the pressure within the warmrectlybecause in those positions the center of gravity or the locket ilfand its contents will be in substantially the samehorizontal plane as the universal joint, andthe washe 28, resting on the shoulder 32 will form a fulcrum through which the force oi gravity, acting downward at the centerxoi the jacket will produce an equal i'orce 1 acting'horizcntallyonthe universal joint 26.

Having described an embodiment of my invention wherein the objects set forth are attained, Iclairnz Lin a portable unit for storing liquid phase oxygen and controlling its'conversion into gas gen, the pressure in the warming coil will have risen to 30 p. s. i.. thereby closing the valve 88. The valve t8 may close, however. before all of the liquid phase oxygen in the warming coil has been converted, and if the conversion of the re- 'mainder of the oxygen raises the pressure in the warming coil to a value higher than the 60 p. s. i.

at which the relief valve 94 is set, some gas phase oxygen will be lost through the valve.

It may therefore be desirable to so adjust the valve 88 by means of the screw I26 as to provide a valve closing pressure which will close the valve It beforeenough liquid phase oxygen has passed into the warming coil to raise the pressure therein above the value at which the relief valve M is set.

phase oxygen,"-a h{eat insulated oxygen containing means, a relief valve, a passageway connecting the upper portion or said oxygen containing means to said reliei valve. a pressure responsive valve having an inleta'nd an outlet opening, a passageway connectingjthe lower portion of said oxygen containingnieans to said inlet opening, a warming coil outsidevs'ald O ygen containing means having one end conntcted-to said outlet opening and the other end cbiinect/ed-to a demand regulator, said pressure responsive-valve being closable by a pre-" determined rise in pressure in said warming coil, and a second reliet'valve connected into said warming coil.

It is noted that all parts of the passageway which connects the opening 80 at the top of the receptacle M- to the relief valve 10 are contained within the evacuated space, the normal conversion rate being therefore quite small. Since none of the gas phase oxygen within this passageway and within the upper portion of the receptacle has any outlet to the warming coil, it may be desirable that the conversion rate within the receptacle and its passageway be-such that in .a given ta'ining means.

. 2. The unit defined in claim 1 wherein the second reliei valve-is set at a materially higher pressure than the first.

3. The unit defined in claim 1 with a housing surrounding the oxygen containing means, a

spring weighing scale in the top of the housing supporting said oxygen containing means, and indicating means on said scale to show the amount of oxygen contained in said oxygen con- 4. In a portable unit for storing liquid phase oxygen and controlling its conversion into gas phase oxygen, a jacket. a container in said jacket with an evacuated chamber between, a gimbal ring pivot'aily supported in said container, a receptacle pivotally supported in said gimbal ring at points ninety degrees removedfrom the points where the glihbal ring is pivotally supported, and having an orifice in the bottom which opens into the gimbal space, weight means carried by said receptacle so placed as to maintain said orifice in its bottom position, a relief valve, a passageperiod of time the increase in volume of gas phase oxygen be but very slightly more than enough to replace the liquid phase oxygen which has been received bythewarming coil in that period, in which case the gas phase oxygen which will be lost through the relief valve it will be kept at a minimum. q

It will be seen that the arrangement of the unit is such that if it isturned on the axis of the hubs l8 and 20, say ninety degrees from the vertical position of Fig. l, the gimbal ring Ml will be in a'horizontal instead of a vertical plane, but

. the weight 52 will rotate the receptacle M through ninety degrees to maintain the receptacle in the upright position shown. d

On the other hand, if the unit is stood on end, say with the hub 29 downward, the. weight 52 will coincidentally turn the gimbal ring 40 ninety degrees on the axis of the bearings 68 and 50 and turn the receptacle 42 ninety degrees on the axis or its bearings 54 and 46. Obviously the weight $2 will always be at the bottom and on the gravity axis.

In either of the positions above given as illustrations, the gauge I28 will continue to read corway connecting the top or said receptacle to said relief valve, a pressure responsive valve having an inlet and an outlet opening with means responsive to a drop in pressure in the outlet open- .ing to open said valve, conduit means connecting the gimbal space to the said inlet opening, a warming coil outside said Jacket having one end connected to said outlet opening and the other end connected to a demand regulator, and a second relief valve-connected into said warming coil.

5. The unit defined in claim 4 wherein the said passageway extends iromthe inside of the receptacle at theito'p, to and through a pivot bearing oi. the receptacle. through a duct formed in the simbal ring, out through the gimbal ring pivot bearing, and, by way of a conduit means, to the relief valve.

8. The unit defined in claim 4 with a housing surrounding the Jacket, a weighing scale carried on said housing, a universal joint connecting said Jacket to said weighing'scale, a disc surrounding and secured to saiddacket near said universal joint, a ring carried by said housing loosely surrounding 'saiddisc, "and a shoulder in said ring positioned just above said disc when said unit is empty or liquid oxygen.

'1. The unit defined in claim 4 with perforated conical baiiies concentrically disposed over the opening in the top of the receptacle and the orifice in the bottom of the receptacle.

8. In a portable unit for storing liquid phase oxygen and controlling its conversion into gas phase oxygen, a heat insulated container, a relief valve having'its inlet opening connected to the upper portion of said container and means operative at a preselected pressure to connect its disto charge opening to the atmosphere, a pressure responsive valve having its inlet opening connected to the lower portion of said container and means responsive to a preselected pressure in its discharge opening to connect its inlet opening to 15 its discharge opening, a warming coil connectingthe discharge opening of the pressure responsive valve to a demand regulator. and a second relief valve having its inlet opening connected to the warming coil, and means operative at a pre- 2 selected pressure to connect its discharge opening to the atmosphere.

rially higher pressure than the pressure responsivevalve.

10. The unit defined in claim 1 wherein there are two stages of pressure, the higher stage governed by the setting of the first relief valve and the lower stage determined by the setting of the pressure responsive valve.

11. The unit defined in claim 1 wherein the pressure responsive valve is interposed between the higher stage of pressure in the container and the lower stage of pressure in the warming coil, and opens only when the pressure in the warming coil tails below the pressure in the container.

JOHN A. WEAVER.

REFERENCES CITED The following references .are of record in the file of this patent:

UNITED STATES PATENTS Dana et a1. Mar. 21, 1944 

